부산대학교 도서관

Background: Exposure to air pollution and, more specifically, particulate matter (PM) is associated with adverse health effects. However, the specific PM characteristics responsible for biological effects have not been defined. Objectives: In this project we examined the composition, sources, and relative toxicity of samples of PM with aerodynamic diameter $\leq 2.5 \mu m$ (PM 2.5 ) collected from sites within the Southeastern Aerosol Research and Characterization (SEARCH) air monitoring network during two seasons. These sites represent four areas with differing sources of PM 2.5 , including local urban versus regional sources, urban areas with different contributions of transportation and industrial sources, and a site influenced by Gulf of Mexico weather patterns. Methods: We collected samples from each site during the winter and summer of 2004 for toxicity testing and for chemical analysis and chemical mass balance-based source apportionment. We also collected PM 2.5 downwind of a series of prescribed forest burns. We assessed the toxicity of the samples by instillation into rat lungs and assessed general toxicity, acute cytotoxicity, and inflammation. Statistical dose-response modeling techniques were used to rank the relative toxicity and compare the seasonal differences at each site. Projection-to-latent-surfaces (PLS) techniques examined the relationships among sources, chemical composition, and toxicologie end points. Results and Conclusions: Urban sites with high contributions from vehicles and industry were most toxic.